This invention relates generally to ink jet printers, and, more particularly, to a mailing machine, including a printing device for printing on a surface that is not flat, such as an envelope.
Ink jet printing mechanisms are well known and have been adapted to a variety of applications and devices, such as: office printers, point of sale devices and postage metering systems. Generally, ink jet printing mechanisms include a print head with multiple ink jet nozzles. Each ink jet nozzle ejects a series of ink drops onto paper or other medium, each drop creating a dot on the paper, until a desired image is achieved.
Typically, a mailing machine utilizes the ink jet printing mechanism in conjunction with a postage metering system included in the mailing machine for dispensing postage. The dispensed postage can be represented as a digital postage indicia which can include a two-dimensional barcode. Automatic processing of a mailpiece requires that the two-dimensional barcode be scanned with a barcode optical recognition device. Accordingly, to be properly scanned, a barcode or other printed image cannot be distorted as viewed from a position normal to the mailpiece.
However, the surface of an envelope traversing a mailing machine typically will not be flat. Placing ink jet dots on a surface that is not flat can cause irregularities and distortions. Distortions can occur, for example, when an irregular topography on a printing surface results in some ink droplets emitted from ink jet nozzles to have a longer fly time than other ink droplets. The transport speed of the mailing machine will continue to move the mail piece at transport speed during the fly time of the ink droplets. The combination of the transport speed and the increased fly time of one droplet relative to another droplet causes a printed image to be warped as viewed from a normal position.
Therefore, it would be advantageous to provide apparatus and methods that overcame the drawbacks of the prior art. In particular, it would be desirable to provide apparatus and methods that facilitate accurate printing of an image on an uneven print surface.
Accordingly, to alleviate problems inherent in the prior art, the present invention introduces systems and methods to facilitate printing on a media surface.
According to some embodiments, a topography of a print surface on a media is determined. A firing time of a print nozzle is then adjusted based upon the determined topography.